146 FUNCTIONS AND INSTINCTS. 



which are distinguished not only by their simple 

 structure, but also by an oscillatory movement 

 which seems to connect them, in some degree, 

 with the animal kingdom. When collected in 

 masses they resemble a piece of green velvet. 

 Some cover considerable spots in moist places ; 

 others live in the water, either fixed to sub- 

 stances contained in it, or floating on the surface. 

 They are generally based on a mucilaginous 

 substance, the remains of those that, having ful- 

 filled their functions, are become a caput mortu- 

 tim. The filaments of which the living plant is 

 composed continually oscillate from right to left, 

 or from left to right, but very irregularly, some 

 going in one direction, others in another ; some 

 remaining stationary while others continue in 

 motion. 



Professor Agardh inclines to the opinion that 

 these oscillating plants owe their existence to 

 different species of animalcules, which at first 

 swim about as animals, and afterwards fix them- 

 selves as plants. This opinion has been adopted 

 by others ; and lately Mr. Unger has stated that 

 he has seen animated particles separate from the 

 parent plant, in a few hours converted into glo- 

 bules of vegetable matter, which subsequently 

 became plants perfectly similar to the individual 

 from which they were produced. 



But surely the motions of these seeds or 

 germes, may be merely mechanical, and may be 



